Ingestion of foods and beverages which cause palate fatigue can negatively affect subsequent ingestions. This is a concern for professionals in the beverage and food sectors as well as consumers in their general appreciation of sensory experiences. For example, winery tasting rooms may try to avoid the palate fatigue problem by pouring wines from white to red and lightest to heaviest astringencies. If unmitigated, this unavoidable problem combined with tasting order biases will have a substantial role on quality perception and therefore negatively misrepresent the product. Currently, the only approaches to solving palate fatigue include water, carbonated water, and crackers or bread. These options are readily available, but are not intended as palate cleansers. They may wash flavors away, but lack the ability to solve the entire problem.
Although inexpensive and portable, crackers and bread can be awkward to consume in between ingestions, leave particles on the palate, and lack the convenience and hydrating power of a beverage.
Often carbonated water may have such a high level of carbonation that it causes sensations of pain on the tongue which can negatively affect the sensory experience.
A need exists for a true palate cleansing beverage that alleviates palate fatigue, allowing for accurate perception of multiple foods and beverages.
Palate fatigue is caused by adaptation—a change in sensitivity to a given stimulus as a result of continued ingestion of that stimulus or a very similar one. Palate fatigue is temporary, but can severely limit the ability to distinguish the stimulus in question. A major concern of wine, tea, beer, coffee or other beverage and food consumers and producers is the continual ingestion of chemical compounds known as tannins. Tannin is the general term used for any large molecular weight plant polyphenol that generally tastes both astringent and bitter when consumed. FIG. 3 is the base unit for most tannin compounds. Tannins are water soluble, have molecular weights in the 500-3000 range and can interact with proteins and polyamides due to the large quantities of hydroxyls and other such groups.
Astringency and bitterness are a sensation and basic taste respectively. Astringency is the puckering or dryness of the mouth that arises through the ingestion of tannic foods. This sensation is caused by salivary proteins precipitating as protein-tannin complexes, decreasing the lubricating effect of saliva. Bitterness is one of the five tastes that are received through taste buds: bitter, salty, sour, sweet, and umami. The two often go together in many beverages and foods: coffee, wine, tea, beer, fruits, legumes, condiments, etc. Although they may both be caused by tannins they are perceived differently and astringency often masks bitterness.
A palate cleanser is a food or beverage which helps to minimize any carryover or adaptation from one beverage or food to the next. In other words, it removes the stimulus that is causing or could cause palate fatigue without imparting any hindering flavors of its own or affecting the consumption of the subsequent food or beverage.